Lightning Arrester is a device used on electrical power systems and telecommunications systems to protect the insulation and conductors of the system from the damaging effects of lightning. The typical lightning arrester has a high-voltage terminal and a ground terminal. Lightning Arrester is a protective device which conducts the high voltage surge on the power system to ground. The earthing screen and ground wires fail to provide protection against traveling waves. The lightning arrester provides protection against surges. The earthing screen and ground wires can well protect the electrical system against direct lightning strokes but they fail to provide protection against traveling waves, which may reach the terminal apparatus. The lightning arresters or surge diverts provide protection against such surges. A lightning arrester or a surge diverted is a protective device, which conducts the high voltage surges on the power system to the ground.